CRON INFO get your URL from https://localhost/mydrupal/admin/reports/status eg something like https://localhost/mydrupal/cron.php?cron_key=lMP7S6A3f5Ue1VvvkFZ6kA-v1AbUIlWUUgaFSN2jeYs

Queues all mail sent by your Drupal site so that it is sent via cron using the Drupal 7 Queue API. This is helpful for large traffic sites where sending a lot of emails per page request can slow things down considerably.

Queue mail can be installed like any other Drupal module

• place it in the modules directory for your site and enable it on the admin/modules page.
• Copy the module url and goto admin/modules/install, then paste the url to Install from a URL textfield, click Install and enable it on the admin/modules page at the last time.

• system (>=7.12)

The configuration page is at admin/config/system/queue_mail, where you can configure the queue mail module and enable challenges for the desired mailId.

Please read Drupal queue api for more information.